Andriod httpurlconnection with WooCommerce OAuth1 API

Please help me.. trying to connect woocommerce website through Android Native app using OAuth1 API.
I am trying this code..
In MainActivity
WE ARE NOT GETTING INPUTSTREAM AND MY APP TERMINATE..
In this code if i use conn.getInputStream(), then my app is directry terminated and if i comment that line then app is not terminated but i do not get any responce from url . Please help